(ODESSA, Ukraine) -- Ukraine appears on the brink of all-out war as government forces are failing to quell uprisings by pro-Russian activists in cities throughout the eastern region of the country.

In the Black Sea port of Odessa, protesters overran a police station Sunday following clashes 48 hours earlier in which dozens of people were killed. Police were finally forced to release prisoners, sparking a joyous celebration by hundreds gathered outside the precinct.

Ukrainian Prime Minister Yuri Sherbakov was also in Odessa Sunday, denouncing the local authorities for doing little to stop Friday's deadly street battles. Meanwhile, Sherbakov also accused Moscow of stirring up its supporters in Ukraine, leading to increasing reports of violence.

While the government has vowed to retake cities where armed insurgents are running free, the military was only able to surround the cities of Slovyansk and Kramatorsk Sunday, seemingly reluctant to move in and engage in all-out warfare.

At the Kremlin, Russian President Vladimir Putin is insisting that Kiev pull its troop out of eastern Ukraine and allow the people there, who are mostly pro-Russia to decide their future.

The fear remains that if the violence escalates further, Russian soldiers and heavy artillery will cross the border to confront the over-matched Ukrainian military.

Should that happen, the White House is preparing to slap much broader economic sanctions against Russia that could target entire sectors of the economy, which would likely prompt Europe to do the same.

However, the Obama administration might hit Russia hard in the pocketbook even if Russian separatist groups disrupt Ukraine's presidential election scheduled for later this month.